: You must use the 32-bit (win32) installer. Even if you are running Windows XP Professional 64-bit, the 64-bit version of Firefox requires Windows 7 or later.
While it is the "latest" for your OS, it is no longer supported with security updates and faces significant compatibility issues on the modern web due to expired security certificates as of March 2025. : You must use the 32-bit (win32) installer
: Pentium 4 or newer with SSE2 support . If your CPU does not support SSE2, the last working version is Firefox 48.0.2. RAM : At least 512 MB (1 GB recommended). Current Limitations : Pentium 4 or newer with SSE2 support
The latest version of Mozilla Firefox that supports Windows XP Professional (including 64-bit editions) is , released on June 26, 2018. Current Limitations The latest version of Mozilla Firefox
: You can find this specific legacy version on the Mozilla FTP Archive or through the Internet Archive . System Requirements
To run this version, your hardware must meet these minimums: : Windows XP SP2 or SP3 .